Electronic device and communication chip thereof

The present invention generally relates to an electronic device, and, more particularly, to an electronic device that supports at least two modulation schemes and shares an antenna.

shows a functional block diagram of a conventional electronic device. The electronic deviceincludes a communication chip, a switch, and an antenna. The communication chipincludes a two-point modulation (TPM) transceiver, an in-phase quadrature modulation (IQM) transceiver, and a digital baseband circuit. The communication chip, the switch, and the antennaare disposed on a circuit board.

The communication chipprovides two modulation schemes (i.e., TPM and IQM), and the two modulation schemes share the antenna. The antennais coupled to a pinor a pinthrough the switch, and the pinand the pinare respectively coupled to the TPM transceiverand the IQM transceiver.

The electronic devicehas the following disadvantages: (1) the communication chiphas a large area (because there are two independent transceivers); and (2) the switchcauses an increase in cost (because the sharing of the antennarequires the switch).

In view of the issues of the prior art, an object of the present invention is to provide an electronic device and its communication chip, so as to make an improvement to the prior art.

According to one aspect of the present invention, a communication chip is provided. The communication chip is configured to transmit a radio frequency (RF) output signal and includes a digital baseband circuit, a reference signal generation circuit, a digital-to-analog converter (DAC), a filter circuit, and a transmitter front-end circuit. The digital baseband circuit is configured to generate a control signal and a digital output signal. The reference signal generation circuit is coupled to the digital baseband circuit and is configured to generate a reference signal. The DAC is coupled to the digital baseband circuit and is configured to convert the digital output signal into an analog output signal. The filter circuit is coupled to the DAC and is configured to filter the analog output signal to generate a filtered analog output signal. The transmitter front-end circuit is coupled to the filter circuit. When the communication chip operates in a first mode, the transmitter front-end circuit up-converts and amplifies the filtered analog output signal according to the reference signal to generate the RF output signal. When the communication chip operates in a second mode, the reference signal generation circuit changes the frequency of the reference signal according to the control signal, and the transmitter front-end circuit amplifies the reference signal to generate the RF output signal.

According to another aspect of the present invention, a communication chip is provided. The communication chip is configured to transmit a radio frequency (RF) output signal or receive an RF input signal, and includes an impedance matching circuit, a pin, a digital baseband circuit, a reference signal generation circuit, a digital-to-analog converter (DAC), a filter circuit, a transmitter front-end circuit, and a receiver circuit. The pin is coupled to the impedance matching circuit. The digital baseband circuit is configured to generate a control signal and a digital output signal. The reference signal generation circuit is coupled to the digital baseband circuit and is configured to generate a reference signal. The DAC is coupled to the digital baseband circuit and is configured to convert the digital output signal into an analog output signal. The filter circuit is coupled to the DAC and is configured to filter the analog output signal to generate a filtered analog output signal. The transmitter front-end circuit is coupled to the filter circuit and the impedance matching circuit and is configured to process the filtered analog output signal or the reference signal to generate the RF output signal, and transmit the RF output signal through the impedance matching circuit and the pin. The receiver circuit is coupled to the impedance matching circuit and is configured to receive the RF input signal through the pin and the impedance matching circuit.

According to still another aspect of the present invention, an electronic device is provided. The electronic device is configured to transmit a radio frequency (RF) output signal or receive an RF input signal, and includes an antenna and a communication chip. The communication chip includes a pin, an impedance matching circuit, a digital baseband circuit, a reference signal generation circuit, a transmitter circuit, and a receiver circuit. The pin is electrically connected to the antenna. The impedance matching circuit is coupled to the pin. The reference signal generation circuit is coupled to the digital baseband circuit. The transmitter circuit is coupled to the digital baseband circuit, the reference signal generation circuit, and the impedance matching circuit and is configured to generate the RF output signal. The receiver circuit is coupled to the digital baseband circuit, the reference signal generation circuit, and the impedance matching circuit and is configured to process the RF input signal. The communication chip transmits the RF output signal through the pin or receives the RF input signal through the pin.

The technical means embodied in the embodiments of the present invention can solve at least one of the problems of the prior art. Therefore, compared to the prior art, the present invention can reduce area and cost.

These and other objectives of the present invention no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiments with reference to the various figures and drawings.

The following description is written by referring to terms of this technical field. If any term is defined in this specification, such term should be interpreted accordingly. In addition, the connection between objects or events in the below-described embodiments can be direct or indirect provided that these embodiments are practicable under such connection. Said “indirect” means that an intermediate object or a physical space exists between the objects, or an intermediate event or a time interval exists between the events.

The disclosure herein includes an electronic device and its communication chip. On account of that some or all elements of the electronic device and its communication chip could be known, the detail of such elements is omitted provided that such detail has little to do with the features of this disclosure, and that this omission nowhere dissatisfies the specification and enablement requirements. A person having ordinary skill in the art can choose components or steps equivalent to those described in this specification to carry out the present invention, which means that the scope of this invention is not limited to the embodiments in the specification.

Reference is made to, which is a functional block diagram of the electronic device according to an embodiment of the present invention. The electronic deviceincludes a communication chipand an antenna. The communication chipincludes a pin, a digital baseband circuit, a reference signal generation circuit, an impedance matching circuit, a receiver circuit, and a transmitter circuit. The receiver circuitincludes a receiver front-end circuit, a filter circuit, and an analog-to-digital converter (ADC). The transmitter circuitincludes a transmitter front-end circuit, a filter circuit, and a digital-to-analog converter (DAC). The impedance matching circuitis used for implementing the impedance matching of the transmission line. The filter circuitand the filter circuitmay be a complex filter or a low-pass filter (LPF). The communication chipis coupled to the antennathrough the pin.

The digital baseband circuitis coupled or electrically connected to the reference signal generation circuit, the receiver circuit, and the transmitter circuit. For the transmitter circuit(more specifically, for the transmitter front-end circuit), the reference signal generation circuitgenerates a reference signal Rf_txin the in-phase quadrature modulation (IQM) mode, and generates a reference signal Rf_txin the two-point modulation (TPM) mode. For the receiver circuit(more specifically, for the receiver front-end circuit), the reference signal generation circuitgenerates a reference signal Rf_rx in both the IQM mode and the TPM mode, and the frequency of the reference signal Rf_rx in the IQM mode can be equal to or not equal to the frequency in the TPM mode.

The digital baseband circuitgenerates a control signal Ctrl and a digital output signal Dout. The digital baseband circuituses the control signal Ctrl to control the reference signal generation circuitto set or adjust (change) the frequency of the reference signal Rf_txand/or the frequency of the reference signal Rf_tx. In the IQM mode, the frequency of the reference signal Rf_txis fixed (i.e., the reference signal Rf_txis a single tone signal). In the TPM mode, the digital baseband circuitperforms frequency modulation (FM) on the reference signal Rf_txthrough the control signal Ctrl (equivalent to performing frequency modulation on the radio frequency (RF) output signal STx), that is, changing the frequency of the reference signal Rf_tx.

In the IQM mode, the transmitter circuitconverts the digital output signal Dout generated by the digital baseband circuitinto the RF output signal STx. The RF output signal STx is coupled to the antennavia the impedance matching circuitand the pin. More specifically, the DACconverts the digital output signal Dout into the analog output signal Sout. The filter circuitfilters the analog output signal Sout to generate the filtered analog output signal Sout′. The transmitter front-end circuitup-converts and amplifies the filtered analog output signal Sout′ according to the reference signal Rf_txto generate the RF output signal STx.

In the TPM mode, the filter circuitand the DACare inactive, while the transmitter front-end circuitamplifies the reference signal Rf_txto generate the RF output signal STx. The RF output signal STx is coupled to the antennavia the impedance matching circuitand the pin.

The receiver circuitconverts the RF input signal SRx, which the communication chipreceives through the antennaand the pin, into the digital input signal Din. More specifically, the receiver front-end circuitdown-converts the RF input signal SRx according to the reference signal Rf_rx to generate the analog input signal Sin. The filter circuitfilters the analog input signal Sin to generate the filtered analog input signal Sin′. The ADCconverts the filtered analog input signal Sin′ into the digital input signal Din.

Due to the shared use of the impedance matching circuitby the receiver circuitand the transmitter circuit, the communication chipcan transmit the RF output signal STx or receive the RF input signal SRx through the same pin (i.e., the pin). Furthermore, because the receiver circuitand the transmitter circuitshare the pin, the antennadoes not need to switch between two pins. In other words, the pinand the antennacan be electrically connected to each other, thereby eliminating the need for the prior-art switchand further reducing the costs.

Reference is made to, which is a detailed functional block diagram of the communication chipaccording to an embodiment of the present invention. The reference signal generation circuitincludes a synthesizer_, a frequency divider circuit_, and a buffer circuit_. The receiver front-end circuitincludes an in-phase quadrature generator (IQ generator)_, a mixer circuit_, and a low noise amplifier (LNA)_. The ADCincludes an ADC_and an ADC_. The transmitter front-end circuitincludes an IQ generator_, a mixer circuit_, a power amplifier driver (PAD)_, and a power amplifier_. The DACincludes a DAC_and a DAC_. The IQM mode and the TPM mode are respectively discussed as follows.

The synthesizer_generates the reference signal Rf_txwith a fixed frequency (i.e., the reference signal Rf_txis a single tone signal), and the frequency divider circuit_and the buffer circuit_are inactive or disabled (in other words, in the IQM mode, the reference signal Rf_txdoes not exist). More specifically, the digital baseband circuitsets the frequency of the reference signal Rf_txwith the control signal Ctrl, and then the synthesizer_operates at that frequency afterwards. Alternatively, the synthesizer_operates at a default frequency (i.e., the frequency of the reference signal Rf_tx) without being controlled by the control signal Ctrl.

In some embodiments, the control signal Ctrl is a digital signal, and the synthesizer_is a digitally controlled synthesizer (e.g., including a digital controlled oscillator (DCO)).

When the communication chiptransmits a signal, the IQ generator_generates an in-phase signal and a quadrature signal based on the reference signal Rf_tx, and the mixer circuit_up-converts the filtered analog output signal Sout′ based on the in-phase signal and the quadrature signal to generate the RF signal S_RF. The RF signal S_RF is amplified by the PAD_and the power amplifier_to generate the RF output signal STx.

When the communication chipreceives a signal, the synthesizer_generates the reference signal Rf_rx, the IQ generator_generates an in-phase signal and a quadrature signal based on the reference signal Rf_rx, and the mixer circuit_down-converts the output signal of the LNA_based on the in-phase signal and the quadrature signal to generate the analog input signal Sin.

When the communication chiptransmits a signal, the digital baseband circuitcontrols the synthesizer_with the control signal Ctrl to change the frequencies of the reference signal Rf_txand the reference signal Rf_tx, in order to achieve the purpose of frequency modulation of the RF output signal STx. The reference signal Rf_txis the signal resulting from the processing of the reference signal Rf_txby the frequency divider circuit_and the buffer circuit_. The PAD_and the power amplifier_amplify the reference signal Rf_txto generate the RF output signal STx. The purpose of the frequency divider circuit_is to make the frequency of the RF output signal STx not equal to the frequency of the reference signal Rf_tx, so as to prevent the large power of the RF output signal STx from affecting the operation of the synthesizer_when the RF output signal STx and the reference signal Rf_txare at the same frequency. The purpose of the buffer circuit_is to enhance the power of the signal to counter the signal attenuation on the transmission line.

In some embodiments, if the power of the RF output signal STx is relatively small or the synthesizer_is relatively ideal, then the frequency divider circuit_can be omitted.

In some embodiments, if the signal attenuation on the transmission line is relatively small, the buffer circuit_can be omitted.

The operation of the receiver front-end circuitin the TPM mode is the same as the operation in the IQM mode, so further elaboration is omitted for brevity. It should be noted that when the communication chipreceives a signal, whether in the IQM mode or TPM mode, the reference signal Rf_rx is a single tone signal. In other words, the digital baseband circuitdoes not perform frequency modulation on the reference signal Rf_rx.

It can be known from above that, in the TPM mode, the digital baseband circuitmodulates the frequency of the reference signal Rf_tx(equivalent to modulating the frequency of the reference signal Rf_txand the RF output signal STx) through the control signal Ctrl.

In some embodiments, since the IQ generator_, the mixer circuit_, the filter circuit, and the DACare inactive in the TPM mode, the digital baseband circuitcan turn off or disable these components to save power.

Reference is made to, which shows an embodiment of the connections among the impedance matching circuit, the PAD_, and the power amplifier_in. In the embodiment of, the impedance matching circuitis a transformer, and the transmitter front-end circuit, in addition to including the PAD_and the power amplifier_, also includes a transformer. The PAD_includes a sub-PADand a sub-PAD, which are used to process (e.g., amplify) the reference signal Rf_txand the RF signal S_RF, respectively. The primary side of the transformeris coupled or electrically connected to the sub-PADand the sub-PAD, while the secondary side is coupled or electrically connected to the power amplifier_. The voltage PA_Vg is the gate bias of the main transistor of the power amplifier_. The primary side of the impedance matching circuitis coupled or electrically connected to the power amplifier_, while the secondary side is coupled or electrically connected to the antenna. The voltage VDD is the power supply voltage of the power amplifier_.

In summary, the communication chipof the present invention supports the IQM mode and the TPM mode, and both modes share the impedance matching circuit, the receiver front-end circuit, the filter circuit, the ADC, part of the reference signal generation circuit, and part of the transmitter front-end circuit. Therefore, compared to the conventional technology, the communication chipof the present invention has the following advantages: (1) saving area (because of shared components); and (2) the switchfrom the prior-art circuit (see) does not need to be set on the circuit board (because both modes share the pin).

The TPM and the IQM are intended to illustrate the invention by way of example and not to limit the scope of the claimed invention. People having ordinary skill in the art may apply the present invention to other types of modulation schemes in accordance with the foregoing discussions.

Note that the shape, size, and ratio of any element in the disclosed figures are exemplary for understanding, not for limiting the scope of this invention.

The aforementioned descriptions represent merely the preferred embodiments of the present invention, without any intention to limit the scope of the present invention thereto. Various equivalent changes, alterations, or modifications based on the claims of the present invention are all consequently viewed as being embraced by the scope of the present invention.